This invention relates to improvements in printing or marking apparatus, particularly of the type in which a hot leaf is pressed by a heated die or printing block against a web or sheet of sheet material so as to transfer pigment from the hot leaf to the sheet material and thereby form the desired marking or imprint on the latter. Hot leaf is generally provided in the form of a roll of a carrier bearing the pigment.
Apparatus of the type described in frequently employed for marking a web of sheet material being advanced intermittently to a wrapping or other machine which utilizes the marked web, and in that case, it is necessary to synchronize the operation of the marking apparatus with the intermittent advance of the web by the associated machine so that the heated die presses the hot leaf against the web only when the web is at rest. Further in such marking apparatus, it is desirable to feed the hot leaf after each marking operation so as to expose a fresh or unused section thereof to the action of the heated die during the next marking operation. Although marking apparatus presently exists for performing the foregoing operation, one disadvantage of such apparatus is that when the roll of hot leaf is exhausted, it is necessary to stop the imprinting device and the wrapping or other associated machine to permit replacing of the hot leaf supply roll. Such down time increases the expense of the wrapping or packaging operation of which the hot leaf imprinter is but one component.
By providing an arrangement which continuously feeds hot leaf from successive supply rolls to the printing station without the necessity of stopping the operation of the imprinter, the foregoing defects in the known imprinters are avoided.